1. Field of the Invention
The present invention relates to a cutter, a method of making a cutter and an apparatus for shaping and cutting the end of tape.
2. Description of the Related Art
For such a purpose of simplifying the operations of applying sheet-like members, a laminated sheet has recently been used in various applications. The laminated sheet includes a self-adhesive sheet which comprises base sheet, a pressure-sensitive adhesive applied onto the base sheet and a release paper disposed on the adhesive.
We have attempted to develop an electronic information processor known as a tape printing apparatus as shown in FIG. 1. A sheet having the aforementioned structure is severed into tape having a width of 5 mm to 40 mm. The tape is coiled into a roll which is in turn disposed in a tape cartridge. The tape cartridge is received in the tape printing apparatus.
The tape is delivered out by a tape delivery mechanism. The necessary letters are printed on the substrate surface of the delivered tape by an operator through a keyboard. Thereafter, the delivered tape is cut away into the necessary length.
Plan and enlarged side views of self-adhesive tape 5 with release paper used in such an apparatus are shown in FIGS. 2 and 3, respectively.
After release paper 9 has been stripped from the self-adhesive tape 5, its base sheet 7 having a pressure-sensitive adhesive 8 is applied to a requisite place to display letters printed thereon.
Such a display is more attractive than hand written letters. Since the tape can be applied to any requisite place without application of any adhesive, an user will not be contaminated on hand and can more rapidly perform the necessary operation. For such a usefulness, the self-adhesive tape with release paper is now being used over a wide range from business use to home use.
Such a self-adhesive tape 5 as shown in FIGS. 2 and 3 is linearly cut by a known cutter which is disposed adjacent to the tape delivery slit 4 of the tape printing apparatus 1.
When the self-adhesive tape 5 is linearly cut by the cutter, the cut tape has such a rectangular contour as shown in FIG. 2. Such a rectangular contour is not only hard but also uniform in appearance. It has been frequently desired that the cut tape has a soft appearance.
When the self-adhesive tape is cut into a rectangular configuration and is applied to a member, the rectangular tape end is likely to be separated from the member at its corners.
To avoid such a problem, one approach may effectively made that the rectangular cut end of the self-adhesive tape 5 is chamfered or rounded as shown in FIG. 4.
Japanese Patent Application Laid-Open No. Hei 4-22654 discloses a cutter which has a shape formed into the configuration of tape end to be cut, the cutter being pressed against the tape to cut the tape end into a desired configuration.
In such a structure, however, it is difficult to cut a part of tape by utilizing a so-called shear angle like known scissors since the cutter is pressed against the tape to be cut. Moreover, since the tape end is at once cut through the whole width thereof, the pressing force must be substantially strong. Otherwise, the whole thickness of the tape end can not be cut through the whole width thereof. However, an unreasonable pressing force to the cutter is likely to raise a problem in durability.
These problems are promoted in cutting a laminated sheet such as the self-adhesive tape 5 rather than a simple sheet of paper, since the thickness of the laminated sheet is larger and the adhesive functions as a cushion.
Furthermore, many types of cutters must be provided for various widths of tape. A structure for selecting and driving one cutter will be complicated with an increased cost. It is further difficult to deal with variability in tape width. In such a case, the chamfered or rounded right- and left-hand corners in the cut tape end became unbalance, leading to an unsatisfactory appearance in the cut tape end.
It is therefore an object of the present invention to solve above problems and to provide a cutter which can efficiently cut a sheet such as self-adhesive tape with release paper with reduced load and cost in an automatic manner, a method of making such a cutter and an apparatus for shaping and cutting the end of tape.
To this end, the present invention provides a cutter comprising:
a stationary cutting blade having at least one stationary cutting edge;
a movable cutting blade having at least one movable cutting edge which moves along a locus including a position opposed to the stationary cutting edge; and
a pair of connecting means for connecting the stationary cutting blade with the movable cutting blade, the pair of connecting means having flexible means for flexibly supporting the movable cutting blade relative to the stationary cutting blade;
wherein a closed loop is formed by the stationary and movable cutting blades and the pair of connecting means.
Since a member to be cut is cut by the stationary and movable cutting blades connected through a pair of connecting means in a closed loop according to the present invention, a cutting stress can be counteracted by the resistance force of the closed loop. Thus, the cutter can be of a simplified structure with an increased rigidity.
Since the stationary and movable cutting blades are formed by the flat sheet members, the cutter can be more inexpensively manufactured.
Since the stationary and movable cutting edges are located opposed to each other on the plane, the cutter can be reduced in thickness and more compactly formed.
Since the member to be cut is sandwiched and cut between the stationary and movable cutting edges located opposed to each other on the plane, the cutting can be more efficiently made with a reduced load than the case where the cutter is pressed against the tape. Furthermore, means for driving the movable cutting blade may be lower in output and smaller in size. The cutter can be more compactly and inexpensively produced.
It is preferable that the stationary cutting blade includes a base portion to be fixed to an apparatus body and a free end portion having the stationary cutting edge. Moreover, it is also preferable that the pair of connecting means extend in a direction perpendicular to a cross direction of the base portion of the stationary cutting blade.
Thus, the connecting means can be disposed parallel to the direction of a tensile stress acting on the pair of connecting means due to the cutting resistance force to improve the cutter strength.
It is preferable that the pair of connecting means have tensile strength which counteracts tensile stress which acts on the pair of connecting means on cutting operation. It is further preferable that the stationary cutting blade has buckling strength which counteracts buckling stress which acts on the stationary cutting blade on cutting operation.
Since the pair of connecting means can counteract the cutting resistance force through the tensile strength when the member to be cut is cut, the strength can be sufficient even if the flexible means formed on the pair of connecting means is flexible. As a result, the cutting can be efficiently made with a reduced load. The drive means can be reduced in output and size. Thus, the cutter can be produced with reduced cost and compactness. Although the stationary cutting blade can counteract the cutting resistance force with the buckling strength, the stationary cutting blade will not be deformed.
It is further preferable that the flexible means has a swing center on the side of the stationary cutting blade, rather than a cutting position between the stationary cutting edge and the movable cutting edge.
Thus, a swing locus of the movable cutting edge is positioned most remote from the central point in the direction of thickness of the movable cutting edge. Therefore, the movable cutting edge will not hit into the stationary cutting edge when the movable cutting edge swings. This avoids such a malfunction as being provided by any interference between the stationary and movable cutting edges. In addition, the cutting can be more efficiently made with a more reduced load.
It is further preferable that the pair of connecting means comprises:
a pair of first connecting means having one ends and another ends, the one ends being connected to the base portion of the stationary cutting blade; and
second connecting means for connecting the another ends of the pair of first connecting means;
wherein a pair of the flexible means are disposed inside of the pair of first connecting means substantially parallel to the pair of first connecting means, the flexible means being connected to the second connecting means and the movable cutting blade.
Thus, the tensile setrength in the pair of first connecting means and the buckling strength in the flexible means can be produced for providing a strength sufficient to counteract the cutting resistance force.
It is further preferable that the flexible portions has a swing center on the side of the movable cutting blade, rather than a cutting position between the stationary cutting edge and the movable cutting edge.
Thus, the flexible means can has its sufficient stroke.
It is further preferable that each of the stationary and movable cutting edges has a relief angle for avoiding a swing locus of the movable cutting edge.
Thus, even if the swing locus of the movable cutting edge interferes the stationry cutting edge, the interference can be reduced by setting the relief angle. As a result, a malfunction caused by the interference can be avoided and the cutting can be efficiently made with a reduced load.
It is further preferable that the stationary cutting edge and the movable cutting edge cut a member which is self-adhesive tape with release paper, and that the movable cutting blade is disposed at a position facing the self-adhesive tape and the stationary cutting blade is disposed at a position facing the release paper.
Thus, the base sheet of the self-adhesive tape can be prevented from producing bowing or burrs on cutting. Further, the base sheet of the self-adhesive tape can provide a better appearance to improve the quality. In addition, the release paper can be more easily stripped since bowing or burrs are produced on the side of release paper.
It is further preferable that at least one of the stationary and movable cutting edges is inclined relative to the respective planes to have different endwise heights in the direction of blade width.
Such an arrangement can form a so-called shear angle. As a result, the cutting can be more efficiently made with a more reduced load, contrary to the case where the cutter is pressed against the tape.
It is further preferable that at least one of the movable cutting blade, flexible means and stationary cutting blade is bent to provide a first gap between the stationary and movable cutting edges, and that a bending position for providing the first gap is different from a swing center of the flexible means for swinging the movable cutting blade.
By preventing the bending position and the swing center line from being identical, the movable cutting edge to swing while maintaining the first gap, resulting in a better cutting quality.
It is further preferable that a second gap between the stationary and movable cutting edges is set between xe2x88x9210 xcexcm and 50 xcexcm, the second gap being created on a cutting operation when the movable cutting edge moves to a position opposed to the stationary cutting edge. More preferably, the second gap is set between xe2x88x925 xcexcm and 10 xcexcm.
When the second gap is provided within said range, the movable cutting edge can reliably pass by the stationary cutting edge. This ensures a reliable cutting quality. It is intended herein that the minus (xe2x88x92) symbol indicates an overlap between the stationary and movable cutting edges while the plus (+) symbol represents a separation between the stationary and movable cutting edges.
It is further preferable that the stationary and movable cutting edges are curved to cut an end corner of a member to be cut into a round shape and has a substantially straight line located adjacent to a position in contact with intersecting two sides at the end corner of the member, the straight line being inclined with a small angle relative to the two sides.
Such an arrangement enables the member to be smoothly cut without large difference in shape between the end corners even if the position of insertion of the member is slightly deviated from a proper position.
It is further preferable that a cutting edge portion formed by the stationary and movable cutting edges is divided into a plurality of sub-sections in the direction of blade width, the sub-sections being different from one another in shape.
Thus, a single cutter can cut the end of the member into any one of various shapes.
It is further preferable that each of the stationary and movable cutting edges is of a rectilinear configuration.
Thus, the member can be rectilinearly cut by the cutting edges in a reliable manner.
It is further preferable that the cutter of the present invention further comprises driving means for driving the movable cutting blade and driven means driven by the driving means, the driven means being disposed on part of the movable cutting blade between the pair of connecting means.
Thus, the movable cutting blade can be automatically driven by the driving means through the driven means that is disposed on part of the movable cutting blade.
It is further preferable that the driven means is disposed at a position adjacent to the movable cutting edge.
Thus, the movable cutting blade can be automatically driven by the driving means with a reduced driving force and in a reliable and stable manner.
According to another aspect of the present invention, a cutter comprises:
a stationary cutting blade having at least one stationary cutting edge;
a movable cutting blade having at least one movable cutting edge which moves along a locus including a position opposed to the stationary cutting edge;
a plurality of connecting means connected to the stationary cutting blade to form a first closed loop; and
a plurality of flexible means connected to the movable cutting blade, wherein the flexible means, a part of the first closed loop, and the stationary cutting blade form a second closed loop inside the first closed loop.
The rigidity in the cutter can be more increased by connecting the first loop with the second loop to share a part of the first loop with the second loop. This can also improve the strength in the connecting and flexible means.
The present invention futher provides a method of making a cutter comprising the steps of:
(a) integrally forming outlines of stationary and movable cutting blades and a pair of connecting means connected thereto with a plate-like member;
(b) cutting the stationary and movable cutting blade, to form a stationary cutting edge on the stationary cutting blade and a movable cutting edge on the movable cutting blade at a position opposed to the stationary cutting edge; and
(c) forming a gap between the stationary and movable cutting edges.
According to the method, a flat sheet member can be used to form an integral combination of the stationary cutting blade, the movable cutting blade, and the pair of connecting means. In addition, the stationary and movable cutting edges can be formed by one and the same means through a single step. If one of the cutting edges is varied in shape, therefore, the shape of the other cutting edge may be varied by the same amount substantially in the same direction. The cutting edges of complicated configuration can be easily formed without any complicated adjustment and with a reduced cost.
By providing an proper gap between the stationary and movable cutting edges, a cutter which can cut a member with a more reduced load and good cutting quality can be produced.
It is preferable that the method further comprises a step of inclining at least one of the stationary and movable cutting edges to provide different endwise heights in a direction of blade width in order to form a shear angle.
By forming the shear angle, the cutter which can more efficiently cut a member with a more reduced load and good cutting quality can be easily produced.
It is further preferable that the step (c) includes a step of bending at least one of the stationary and movable cutting blade.
Thus, the bending can easily form a proper gap between the stationary and movable cutting edges.
It is further preferable that the step (c) includes a step of upsetting the pair of connecting means so as to increase length of the pair of connecting means.
The upsetting can easily form a proper gap between the stationary and movable cutting edges.
It is further preferable that the step (c) is carried out immediately after the step (b) is performed and before the movable cutting edge is returned to its original state.
By carrying out necessary steps to form a gap before the movable cutting edge is returned to its original state, a proper gap can be formed without any interference. As a result, the cutting edges can be prevented from being damaged with easy formation of the proper gap.
It is further preferable that the step (a) includes a step of separating the movable cutting blade from the pair of connecting means, and the method further comprising a step of connecting the movable cutting blade with the pair of connecting means with a connecting plate before the step (b).
By connecting the movable cutting blade with the pair of connecting means by a separate connecting plate, any deviation will not be created between the stationary and movable cutting blades, ans the stationary and movable cutting blades of complicated configuration can be exactly formed.
It is further preferable that the step (b) includes a wire cutting step or a laser cutting step.
The wire or laser cutting step can easily cut the member to be cut and form the proper gap between the stationary and movable cutting edges.
The present invention further provides an apparatus for shaping and cutting the end of tape, characterized by shaping and cutting the corners of the tape end by the use of the cutter of the present invention as described above.
Such an apparatus can provide a reduced space in which the cutter is to be installed and also reliably shape and cut the tape end.